Radio receiving set



SeptQ29, 1931. w. J. KAYSE R RADIO RECEIVING SET Filed Nov. 13. 1929 2 Shets-Sheei. 1

Sept. 29,1931. w. J. KAYSER RADIO RECEIVING SET 7 Filed Nov. 13. 1929 2 Sheets-Sheet 2 i if y a w W 5 A w M o m H lku 5 a 7 n 0 w x w a W. m W. Z 5 V. 4 f z 2 2 Q? Wm 2. a a W .0 1 w 1% 1 E 9 MW Um :E. o f

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l' atentecl Sept. 29, 1931 "PATENTYVOFFICHLE wILLrAM :r. KAYsER,or LITTLE ROCK, ARKANSAS RADIOVREGEYIVING snr A lication-fl ed November 1a, 1929. Serial no. 4.06920.

This invention relates to an improved crystal'radio receiving set.

One object of the invention is to provide 7 a receivingset of :this character having-oer. tam peculiaritles of structure whereby 1t is possible to receive signals from stations located at greater distances than" has been possible-with previous crystal sets.

Another object of the invention is to provide aset which will be characterized by simplicity throughout. I

A further object of the invention is to provide a setwherein certain parts are employed to serve a dual function, thusob-viat- 1 inga duplication of parts and consequent complication of structure. j

Other objects of the invention not specifically mentioned in the foregoing will be apparent during the course of the following description. I

In' the drawings:

Figure 1 is a perspective view of the set. I Figure 2 is a front elevation of the set with the front'wall removed.

Figure 3 is a horizontal section'alview of the set on the line 3-3 of Figure .2, looking in the direction indicated by thearrows.

Figure 4 is a vertical sectional view of the set on the-line of Figure 2, looking in 39 the direction indicated by the arrows.

Figure 5 is a fragmentary vertical sectional View showing the crystal detector and mounting employed. v

Figure 6 is a diagrammatic View showing the circuit employed.

In carrying the invention into elfect, I employ an oblong rectangular cabinet which is preferably formed of bakelite or other insulating material. The cabinet includes a bottom wall 1, front and rear walls 2and 3, and end walls 4 and 5. Hinged to the rear wall 3 is a lid 6 normally closing the cabinet.

5 Mounted on the bottom wall 1 at one end through the end wall 4. Removably secured the upper end portion of the stem isa crys- The walls are held in proper relation by screws 7. The-end walls land 5 are thereof and in close spaced relation to the rear wall3 an antenna bracket having one 4 leg 9 upstanding from thebottom wallv and the other leg 10 secured to the bottom wall by means of a boltll'. The leg 10 extends IE to the free. end portion of said'leg 10 is a i bindding post 12 to accommodate. an antenna lea." 1 V i As can be more. clearly seen in Figure 4: .of'the drawings, the rear wall of the cabinet is provided with a medially disposedrecess and mountedaon said wall is aflcrystal bracket havingone .leg 13, snugly seated-in the recess and. held therein by a bolt 14.

The other leg 15 of this bracket extends in horizontal spaced .relationto the panel and is, a wire 19. The'opposite end of the wire 19isconnected with the crystal bracket by the'nut 17.- Screwed on-the stem and overlying the upper face of the panel 8 is a nut 20.-- The. panel is clamped in position. between the nuts 17 and 20 and screwed on tal receiving cup 21. Carried inthe cup is a crystal22 which isclamped in said cup by -a.radial set screw 23.

, --Mounted, on the end wall 5 of the cabinet 1 in alignment with the antenna bracket isa cat-whisker bracket having one leg 24 seinwardly of said opening is abolt 28. Se-

cured at one end by said bolt is a preferably flat. resilient cat-whisker 29 which extends freelythrough said opening and upwardly (on through an opening in the panel 8.- This cat-whisker is bowed longitudinally and tapered toward its free end to form a point for engagement with the crystal 22. Tightly fitting in the opening in the panel is a plug 30 of insulating material which plug snugly surrounds the cat-whisker and provides a brace therefor. Mounted on the upper margin of the end wall 5 is a pair of binding posts 31 and 32, to which a pair of telephones may be connected. Electrically connecting the bolt 28 with the binding'post 3lisawire33. Mounted on the bottom wall 1 of the cabinet and near the frontwall thereof, is a loop bracket having one leg 34 upstanding from said wall and the other leg 35 thereof secured to the bottom wall by a.bolt 36. Mounted on the bottom wall in alignment with the loop bracket is asecond loop bracket having a leg 37 upstanding from the bottom wall and a leg 38 secured to the bottom wall by abolt 39, the leg 38 extending at its free end through the endwall 5. Removably fixed on the outer end portion of the leg 38 is a binding post 40 to receive a ground lead. Extending back and forth between the loop brackets through spaced openings in thelegs 34 and37 thereof are preferably copper wires forming a loop 41, corresponding ends of saidwires being secured to the bolt, 36 and opposite corre sponding ends of said wires being secured to the binding post 32. 'The loop wires are bare and one of said wires is preferably tinned. Wrapped about said wires and secured at one end to. the bolt 36 is a bare copper wire 42 securing the intermediate portions of the strands of the loop wires'in bunched parallel relation, this wire being untinneda Resting on the bottom wall of the casing is an inductance coil 43 having one terminal secured to the bolt 36 of the loop bracket. Securing thecoil 43 to the bottom wall 1 are clamps 44. As can. be readily seen in Figurefi of the drawings, the coil is connected across the terminals of the antenna bracket and the adjacent 100p bracket. As can be understood from a study of 'Figure 6 of the drawings, impulses received on the antenna are conveyed to the antenna post, thence through the wire 19 to the crystal, thence through the cat-whisker 29 tothe terminal 31 of the telephones, thence wires 41 extend in close proximity to each other throughout their length, while the intermediate portions of the strands thereof are held by the wire 42 in bunched substantially. parallel relation, a slight capacitive coupling is formed between the strands,

thereby providing a small capacity in the ground lead which has well known advantageous effects in that signals are strengthened and stations received that would not otherwise be received.

What is claimed is:

l. A radio receiving set including a cabinet, 2. panel mounted in said cabinet, a bracket mounted on a wall of the cabinet, a crystal cup stem carried by the bracket and extending through the panel, means sesaid bracket andextending through the panel to cooperatewith the crystal, said panel and bracket cooperating to provide a rigid support for the cat-whisker, and circuit connections for the crystal and catwhisker.

3. A radio receiving set including a. cabinet, a panel carried in the cabinet and provided with an opening, a crystal mounted on the panel, a bracket mounted on a wall of the cabinet and having oneleg projecting to lie beneath the opening, a cat whisker mounted. on the bracket and projecting upwardly through the opening to. coact with the crystal, a plug carried by the panel in the opening and surrounding the cat whisker at the panel, said panel and plug cooperat-' ing with the bracket for rigidly mounting the inner end portion of the catwhisker, and circuit connections for said-crystal and cat whisker.

In testimony whereofI-afiix my signature.

WILLIAM J. KAYSER. [L. 8.] 

